JP2001192612A - Binder-containing composition containing filler, method for producing the same and method for using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a binder-contg. composition capable of giving magnetic recording media having such sufficient hardness and wear resistance as to be preservable and operable even at high temperatures and high humidities, thus favorably usable for producing magnetic recording media. SOLUTION: This binder-contg. composition comprises at least one thermoplastic blocked copolyurethane having at least one soft segment A and at least one hard segment B and at least one kind of inorganic filler; wherein the thermoplastic blocked copolyurethane is such that the at least one hard segment B has a structural moiety shown by the formula I. This binder-contg. composition can be used for producing, in particular magnetic recording media.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thermoplastic block copolyurethane having at least one soft segment A and at least one hard segment B, wherein said at least one hard segment B has the formula I

[0002]

Embedded image A thermoplastic block copolyurethane containing a structural part represented by, and an inorganic filler, a binder-containing composition containing at least, a method for producing the binder-containing composition, and
In particular, it relates to a method of using the binder-containing composition for producing a magnetic recording medium.

[0003]

BACKGROUND OF THE INVENTION Various groups of substances are known as binders suitable for use in magnetic recording media. Polyurethane has proven to be a very effective material today, especially because it significantly improves the resilience of magnetic recording media or the coating layers of such magnetic recording media. However, in the case of polyurethane, problems of lack of hardness and wear durability are often recognized.

This problem is described, for example, in German Patent Application 19
No. 6,26824.9. The polyurethanes obtained by the above application significantly improve the hardness and abrasion durability values, but the recording stability, under special conditions,
For example, when stored or operated at a high temperature, it decreases.

[0005]

SUMMARY OF THE INVENTION In order to avoid these problems, polyurethanes used for magnetic recording media include:
For example, ionic anchor groups have been introduced. EP-A 0 681 289 therefore discloses ionic phosphonates which are suitable for use as binders for magnetic recording media. The above application discloses polyurethanes containing such ionic phosphonates and methods of using the polyurethanes in magnetic recording media. However, the polyurethane having an ionic anchor group,
In general, there is a problem that it exhibits high water absorption, particularly in a high-temperature, high-humidity atmosphere. When the above polyurethane is used for a magnetic recording medium (for example, a tape), as the water absorption increases, the glass transition temperature of the magnetic recording medium decreases, and in general, the abrasion and adhesiveness of the tape increase. Adheres to the read head and data is lost.

Therefore, a binder or a binder-containing composition that can be used, for example, in the production of a magnetic recording medium must avoid the above-mentioned problems.

[0007] An object of the present invention is to provide a binder or a binder-containing composition capable of avoiding the above problems.

[0008]

SUMMARY OF THE INVENTION The object of the present invention is to provide at least one thermoplastic filler having at least one inorganic filler and at least one soft segment A and at least one hard segment B. It has been found that this is achieved by a binder-containing composition containing at least a block copolyurethane.

Accordingly, the present invention provides an inorganic filler and a thermoplastic block copolyurethane having at least one soft segment A and at least one hard segment B or a mixture of two or more such copolyurethanes;
Wherein the at least one hard segment B is of the formula I

[0010]

Embedded image (Wherein, R ¹ and R ³ may be the same or different, and a substituted or unsubstituted aromatic or heteroaromatic group having 4 to 40 carbon atoms is represented by R ² and R ⁴ Represents hydrogen, or R ¹ , R ² , R ³ and R ⁴ represent a substantially fully fluorinated alkyl group having 1 to 10 carbon atoms, and R ⁵ and R ⁶ represent A substituted or unsubstituted linear or branched aliphatic group or a substituted or unsubstituted alicyclic group or a substituted or unsubstituted aliphatic group having 4 to 40 carbon atoms, which may be the same or different. A substituted aromatic group, and n is 1 to 100).

As used herein, the term "binder-containing composition" means a composite comprising at least one binder and at least one inorganic filler.

As used herein, "binder" means a polymer or a mixture of two or more polymers that is substantially included in the composition of the magnetic storage medium after completion of chemical or physical drying. I do. As used herein, a binder may include, for example, only one type of polymer, ie, only one particular type of polymer molecule. At this time, the individual polymer molecules belonging to the same type are molecules differing only in the molecular weight, and the molecular weight in this case is established by the molecular weight distribution obtained by a selected polymerization method. If only one type of polymer molecule is present in the binder, the chemical composition of such polymer molecules is substantially the same. However, the binder of the present invention may have two or more different types of polymer molecules. Different types of polymer molecules, for example, differ in either molecular weight distribution, molecular weight, or chemical composition, depending on the type. However, different types of polymer molecules may differ in two or more of the above properties.

[0013] As used herein, "hard segment" means a segment of a thermoplastic block copolyurethane molecule that exhibits a glass transition temperature of at least about 50 ° C.

As far as the present invention is concerned, "a soft segment is a segment of a thermoplastic block copolyurethane molecule which is covalently bonded to a hard segment, and the operating temperature of a magnetic recording medium made from the novel copolyurethane of the present invention. Segments exhibiting a lower glass transition temperature, for example, less than about 30 ° C., preferably less than about 20 ° C. are meant.

As used herein, "anchor group" means a functional group capable of attracting interaction with an ionic or non-ionic polar compound. In particular, by "anchor group" is meant a functional group capable of attracting interaction with the surface of the inorganic filler material, especially the surface of the inorganic magnetic or magnetizable powder.

In the following description, for simplicity, the "thermoplastic block copolyurethane" used for the purposes of the present invention is referred to as "thermoplastic polyurethane" or simply "polyurethane". When referring to polyurethanes that are not thermoplastic or polyurethanes that are not block copolymers, they are explicitly indicated below.

As used herein, "inorganic filler" means a particulate filler having a particle size of about 100 nm to about 1 mm. Suitable inorganic fillers include, for example, chalk, titanium dioxide, silica, or other minerals that can also be processed into particles, or metals, carbon black, or especially magnetic or magnetizable powders, such as γ-Fe ₂ O ₃ , γ-Fe ₃ O ₄ , CrO ₂ ,
An oxide powder such as Co-modified Fe ₂ O ₃ , or Fe, C
o, and metal powders such as Ni. As is generally known, other elements or compounds can be mixed with the powder.

[0018]

DETAILED DESCRIPTION OF THE INVENTION The thermoplastic polyurethanes contained in the novel binder-containing compositions according to the invention each comprise at least one compound of the formula I

[0019]

Embedded image Has at least one hard segment B having a structural portion represented by Here, R ¹ and R ³ may be the same or different, and a substituted or unsubstituted aromatic or heteroaromatic group having 4 to 40 carbon atoms is represented by R
² and R ⁴ each represent hydrogen, or R ¹ , R ² ,
R ³ and R ⁴ represent a substantially fully fluorinated alkyl group having 1 to 10 carbon atoms.

In a preferred embodiment of the present invention, R ² and R ⁴
Is one or two of the groups shown below.

[0021]

Embedded image

In a further preferred embodiment of the present invention, R
² and R ⁴ are the same. In another preferred form of the invention, R ² and R ⁴ are methoxyphenyl or trimethoxyphenyl groups. In a further preferred form of the invention, R ² and R ⁴ are hydrogen.

For the purposes of the present invention, R ⁵ and R
⁶ may be the same or different and have from about 4 to about 40 carbon atoms, a substituted or unsubstituted linear or branched aliphatic group or a substituted or unsubstituted cycloaliphatic; Represents a group or a substituted or unsubstituted aromatic group. Preferred aliphatic groups include, for example, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, and a series of higher homologs obtained by extending each of the above hydrocarbon chains with one CH ₂ group. Body. As R ⁵ and R ⁶ , a divalent alicyclic group such as cyclohexylene, dicyclohexylmethylene or 3,3,5-trimethylcyclohexylene is also preferable.

In a preferred form of the invention, R ⁵ and R ⁶
May be the same or different, and have 4 to 4 carbon atoms.
It is a substituted or unsubstituted linear or branched aliphatic group having 10 or a substituted or unsubstituted aromatic group having 6 to 18 carbon atoms.

In a preferred form of the invention, R ⁵ and R ⁶
Is toluylene, tetramethylxylylene, naphthylene, tetrahydronaphthylene or diphenylenemethane.

The synthesis of the hard segment B present in the thermoplastic polyurethane for the purposes of the present invention can be carried out by a cross-cycloaddition reaction between one azine and two polyisocyanates. For the purposes of the present invention, it is preferred to use diisocyanates as polyisocyanates, but it is also possible to use isocyanates having a functionality of more than 2 or mixtures thereof. Use of the azines of the formula III for the synthesis of thermoplastic polyurethanes which can be used in the novel binder-containing compositions, in particular for the synthesis of the hard segments B contained in these thermoplastic polyurethanes I do.

[0027]

Embedded imageWhere R¹And R^TwoHas the same meaning as described above. The present invention
In a preferred form of R ¹And R^TwoAnd described
As shown at the time, p-methoxybenzoaldazine
Or trimethoxybenzoaldazine represented by formula III
Used as azine. In a preferred form of the invention,
Formula III to obtain the corresponding hard segment B
The reaction of the azine that is carried out is one type of polyisocyanate or
Is performed using a mixture of two or more polyisocyanates.
U.

By appropriately selecting the stoichiometric ratio of azine to diisocyanate, an oligomer compound or polymer compound having two isocyanate groups at the chain end can be synthesized according to the above reaction. Such a compound is a compound represented by Formula II.

[0029]

Embedded image

Suitable for the synthesis of hard segment B in thermoplastic polyurethane obtained as described above,
The polymeric diisocyanate can have a molecular weight ranging from about 500 to about 30,000 for the purposes of the present invention. Depending on the azine and diisocyanate used, different molecular weight compounds are obtained. In a preferred embodiment of the present invention, the compound of formula II used for the synthesis of hard segment B comprises from about 1000 to about 2
Molecular weight in the range of 0000, for example, about 1100 to about 180
It has a molecular weight in the range of 00. In a further preferred form of the invention, the compound of formula II used for the synthesis of hard segment B has a molecular weight in the range from about 1200 to about 5000, in particular in the range from about 1300 to about 3000.

In principle, all diisocyanates which can form a polymeric diisocyanate of the formula II satisfying the above-specified ranges by reaction with azine are all compounds of the formula II Suitable for. In a preferred embodiment of the present invention, for example, tetramethylene 1,4
Linear aliphatic diisocyanates such as diisocyanate, pentamethylene 1,5-diisocyanate or hexamethylene 1,6-diisocyanate, cyclohexylene 1,4-diisocyanate, dicyclohexyl An alicyclic diisocyanate, such as methane diisocyanate or isophorone diisocyanate (IPDI), is used. Suitable diisocyanates for the purpose of the present invention include, in addition, toluylene 2,4-diisocyanate (2,4-TDI), toluylene 2,6-diisocyanate (2,6-TDI), An isomer mixture of TDI, m-tetramethylxylylene diisocyanate (T
MXDI), p-tetramethylxylylene diisocyanate, naphthylene 1,5-diisocyanate, tetrahydronaphthylene 1,5-diisocyanate, diphenylmethane 2,2'-diisocyanate, diphenylmethane 2,4'-diisocyanate And aromatic diisocyanates such as diphenylmethane 4,4'-diisocyanate, and mixtures of two or more of the above diisocyanates. For the purposes of the present invention, it is of course also possible to use a mixture of two or more azines or a mixture of two or more diisocyanates or both in the reaction of azine with diisocyanate, Can be assumed. In this case, a compound represented by formula II is obtained in which R ¹ and R ³ are different from R ⁵ and R ⁶ . However, in a preferred form of the invention, the compound of formula II is
R ¹ and R ^{3 in} addition to R ⁵ and R ⁶ have the same group.

Suitable methods for synthesizing compounds of formula II are described, for example, in G. Polymers by Maier
by 1,3-dipolar cyclodit
ion reaction: the “criss-
cross "cyclodition, Macr
omol. Chem. Phys. 197 (19
96), 3067-3090. In particular, pages 3078-3088 of this document provide a description relating to the present invention.

For the purposes of the present invention, for the synthesis of a thermoplastic polyurethane having a structural part of the formula I in the hard segment B, a compound of the formula II
A compound suitable for soft segment A having at least one functional group Y capable of reacting with the isocyanate group of the compound of formula II to form a covalent bond is reacted.

The novel polyurethane contains at least one soft segment A. However, for the purposes of the present invention, the thermoplastic polyurethane may comprise two or more different types of soft segment A. The two or more different types of soft segments A may be, for example, the same soft segment, that is, a soft segment having substantially the same chemical composition. However, two or more different soft segments A may be used for the purposes of the present invention. Therefore, the thermoplastic polyurethane used in the novel binder of the present invention is:
The soft segment A may have, for example, polyester and polyether.

As soft segment A, in principle, all polymers which are soluble in the solvent used and which preferably have a glass transition temperature lower than 20 ° C. are preferred.
Examples include polyesters, polyethers, polyacetals, polycarbonates, polyester ethers and the like.

The above compounds suitable for use as soft segment A have at least one functional group Y. In a preferred form of the invention, compounds suitable as soft segment A have at least two functional groups Y. In a further preferred form of the invention, the functional group Y is attached to the chain end of the compound used as soft segment A.

In principle, Y is a functional group which can react with NCO groups to form a covalent bond. In a preferred form of the invention, Y is OH, NH ₂ , NHR, SH
Or COOH. At this time, in the formula NHR,
R represents a linear or branched saturated or unsaturated alkyl group having 1 to 24 carbon atoms, or 6 to 24 carbon atoms.
There are 24 aryl groups.

In a further preferred form of the invention, Y is
OH, NH and NR groups, especially OH groups. Hereinafter, compounds suitable for the synthesis of soft segment A will be described. For clarity, unless otherwise noted, compounds are OH
Is a compound having However, for the purposes of the present invention, instead of OH groups in the compounds shown below, N
A corresponding compound having another functional group capable of reacting with a CO group, for example, one of the functional groups other than the OH group among the functional groups indicated for Y, is present or synthesized. You can use it if you can.

Polyesters suitable for the synthesis of soft segments include, for example, substantially straight-chain, preferably OH groups at the chain ends, preferably having 2 or 3 and particularly preferably 2 terminal OH groups. It is a polymer. Polyester polyols are straight-chain or branched saturated or unsaturated aliphatic dicarboxylic acids having 4 to about 15, preferably 4 to about 10 carbon atoms, or the corresponding suitable aromatic dicarboxylic acids. Glycols, preferably having about 2 carbon atoms
It can be synthesized by a simple method such as a method of esterifying with a glycol of about 25 to about 25 or a method of polymerizing a lactone having about 3 to about 20 carbon atoms. As dicarboxylic acids that can be used, for example, glutaric acid,
Pimelic acid, suberic acid, sebacic acid, dodecanoic acid, or adipic acid or succinic acid is preferred.
Mixtures of more than one of the above dicarboxylic acids are mentioned. As the aromatic dicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, or a mixture of two or more of these dicarboxylic acids is preferable. One or more aromatic dicarboxylic acids and aliphatic dicarboxylic acids or another aromatic dicarboxylic acid,
Mixtures of, for example, diphenic acid, pentadienoic acid, succinic acid or adipic acid are also preferred.

For the synthesis of polyester polyols, instead of dicarboxylic acids, corresponding acid derivatives such as, for example, carboxylic anhydrides, esters, in particular methyl esters, or carbonyl chloride, may be used if these compounds are obtained. It is preferred to use.

Polyester polyols suitable for use as soft segments for the purposes of the present invention can be synthesized by reacting a dicarboxylic acid with the corresponding glycol. In principle, glycols suitable for the synthesis of polyester polyols are straight-chain or branched, saturated or unsaturated aliphatic or aromatic glycols. For example, diethylene glycol, 1,2-ethanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4
-Butanediol, 1,5-pentanediol, 1,6-
Hexanediol, 1,7-heptanediol, 1,8
-Octanediol, 1,9-nonanediol, 1,1
0-decanediol and the corresponding higher homologs that can be formed by stepwise extending the carbon chain of these compounds, and further include, for example, 2,2,4-trimethyl-1,5 -Pentanediol, 2,2-dimethyl-1,3-propanediol, 1,4-dimethylolcyclohexane, 1,4-diethanolcyclohexane, 2-methyl-2-butyl-1,3-propanediol, 2,2 -Dimethyl-1,4-butanediol, neopentyl glycol hydroxypivalate, diethylene glycol, triethylene glycol, methyldiethanolamine, or an aromatic having 8 to 30 carbon atoms-
Aliphatic diols or aromatic-alicyclic diols (where the aromatic structure is a heterocyclic system or preferably a homocyclic system such as, for example, naphthalene, or in particular a benzene derivative such as, for example, bisphenol A) ), Symmetric diethoxylated bisphenol A,
Symmetric dipropoxylated bisphenol A, higher ethoxylated or propoxylated bisphenol A derivatives or bisphenol F derivatives, hydrides of said bisphenol A and bisphenol F derivatives, or mixtures of the above compounds or two or more of the above compounds And alkylene oxide having 2 to about 8 carbon atoms or 2
Reaction products of a mixture of one or more of the alkylene oxides.

In a preferred embodiment of the present invention, 1,2-ethanediol, 1,3-propanediol, 2-methyl-
1,3-propanediol, 1,4-butanediol,
1,6-hexanediol, 2,2-dimethyl-1,3
Using ethoxylated or propoxylated propanediol, 1,4-dimethylolcyclohexane, 1,4-diethanolcyclohexane and 2,2-bis (4-hydroxyphenylene) propane (bisphenol A). Depending on the desired properties for the thermoplastic polyurethane having the corresponding soft segment, the polyester polyols described above may be used alone for the production of thermoplastic polyurethanes, and two or more of the above polyester polyols may be used in various ways. Mixtures mixed in proportions may be used. As the lactone used for the synthesis of the polyester polyol, for example, α, α-dimethyl-γ-propiolactone, β-butyrolactone and ε-caprolactone are preferred.

Polyether polyols can also be used in the synthesis of the thermoplastic polyurethanes described above in soft segment A.
It is suitable for use as. In this case, the polyether polyol means a substantially linear substance having a terminal OH group and an ether bond as described above.
Suitable polyether polyols are, for example, by polymerizing a cyclic ether such as tetrahydrofuran, or by adding an alkylene oxide having 2 to 4 carbon atoms in one or more alkylene moieties and two reactive hydrogen atoms. It can be synthesized by reacting with an initiator molecule. Examples of suitable alkylene oxides include ethylene oxide, 1,2-propylene oxide, epichlorohydrin, 1,2-butylene oxide, 2,2
Examples include 3-butylene oxide or a mixture of two or more thereof.

Suitable polyester polyols and polyether polyols, and their synthesis, are described, for example, in EP-B 0 416 386.

For the purposes of the present invention, for example, polycarbonate can also be used as soft segment A. In a preferred form of the invention, a polycarbonate having at least two substantially linear OH groups, preferably terminal OH groups, is used. The corresponding polycarbonate polyols are, for example, the above-mentioned bifunctional alcohols or mixtures of two or more such alcohols, phosgene,
Can be synthesized by reacting Suitable polycarbonate polyols, for example those based on 1,6-hexanediol, and their synthesis are described, for example, in US Pat. No. 4,131,731.

For example, aliphatic alcohols having 3 or more functional groups and having 3 to about 15, preferably about 3 to about 10 carbon atoms are also useful in the synthesis of soft segments in thermoplastic polyurethanes. Can be used in an amount of up to about 5% by mass based on the total mass of the soft segments contained in the sucrose. Corresponding suitable compounds include, for example, trimethylolpropane, triethylolpropane, glycerol, pentaerythritol, sorbitol, mannitol and also sugar alcohols having up to about 10 OH groups per molecule. Corresponding derivatives of the above compounds obtained by reaction of the above compounds with alkylene oxides having 2 to about 4 carbon atoms or a mixture of two or more such alkylene oxides are also suitably used for the synthesis of soft segments. be able to. As still another modification,
A carboxylic acid having three or more functional groups or a derivative thereof can also be used. The above compounds can be used alone or as a mixture of two or more of the above compounds.

In a preferred embodiment of the present invention, for example, a polyester obtained by reacting adipic acid or isophthalic acid and / or a mixture thereof with 1,6-hexanediol or cyclohexanedimethanol or a mixture thereof is used as soft segment A. use.

In a preferred form of the invention, soft segment A has a glass transition temperature ranging from about -50 ° C to about 20 ° C. In a more preferred embodiment of the present invention, the soft segment A has a glass transition temperature of about -30C to about 0C.
Range. To ensure the desired mechanical properties for the novel binder of the present invention, the soft segment A
Must have a molecular weight of about 500 to about 25,000. In a preferred form of the invention, from about 2000 to about 100
For example, a soft segment A having a molecular weight of about 3000 to about 7000 is used.

Compounds suitable for use as soft segment A belonging to the above class of compounds may be those which already have a molecular weight in the range of molecular weights suitable for use as soft segment A. . However, for the synthesis of soft segment A, it is also possible to use compounds belonging to the above class of compounds having a molecular weight suitable for use as soft segment A or smaller than the desired molecular weight. In this case, for the purposes of the present invention, the compounds belonging to the class of compounds described above are reacted with the corresponding bifunctional compounds or compounds with a functionality greater than 2 until the required or desired molecular weight is reached. May be extended. Depending on the terminal group Y, for example, dicarboxylic acids, bifunctional epoxy compounds or diisocyanates are suitable for this purpose,
In a preferred embodiment of the present invention, a diisocyanate is used.

In principle, the extended soft segment A
Bifunctional compounds or compounds having a functionality greater than 2 that bring the glass transition temperature of the compound to the desired range can be used for the purpose of increasing the molecular weight described above. In this case, in a preferred embodiment of the invention, therefore, diisocyanates, preferably diisocyanates having 6 to 30 carbon atoms, are used as compounds for increasing the molecular weight for the synthesis of soft segment A. Specific examples include linear aliphatic diisocyanates such as tetramethylene 1,4-diisocyanate, pentamethylene 1,5-diisocyanate or hexamethylene 1,6-diisocyanate; Alicyclic diisocyanates such as 4-cyclohexylene diisocyanate, dicyclohexylmethane diisocyanate or isophorone diisocyanate (IPDI), toluylene 2,4-diisocyanate (2,4-TDI), toluylene 2 , 6-Diisocyanate (2,6-TDI), an isomer mixture of these TDIs, m-tetramethylxylylene diisocyanate (TMXDI), p-tetramethylxylylene diisocyanate, naphthylene 1,5-diisocyanate Nart,
Aromatic diisocyanates such as tetrahydronaphthylene 1,5-diisocyanate, diphenylmethane 2,2'-diisocyanate, diphenylmethane 2,4'-diisocyanate and diphenylmethane 4,4'-diisocyanate; Aromatic diisocyanates, and mixtures of two or more of the above isocyanates.
In a further preferred embodiment of the present invention, a diisocyanate having an aromatic ring in the molecule is used.

If desired, relatively low molecular weight diols can also be used to increase molecular weight. Examples of these are diethylene glycol, 1,
2-ethanediol, 1,3-propanediol, 2-
Methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol , 1,10-decanediol, and the corresponding higher homologs that can be synthesized by stepwise extending the carbon chain of the compound, and, for example, 2,2,4-trimethyl-1,5-pentanediol,
2,2-dimethyl-1,3-pentanediol, 1,4
-Dimethylolcyclohexane, 1,4-diethanolcyclohexane, 2-methyl-2-butyl-1,3-propanediol, 2,2-dimethyl-1,4-butanediol, neopentyl glycol hydropivalate, diethylene glycol, triethylene glycol Ethylene glycol, methyldiethanolamine, or an aromatic-aliphatic diol or an aromatic-alicyclic diol having 8 to 30 carbon atoms (as an aromatic structure, a heterocyclic ring or, preferably, a homocyclic ring such as naphthalene) System, or especially bisphenol A
Can be used. ).

Further, if necessary, a low molecular weight amino compound can be used in the reaction for increasing the molecular weight. For example, primary amines having 2 to about 20 carbon atoms, such as 2 to about 12 carbon atoms, such as ethylamine, n-propylamine, isopropylamine, s-propylamine, t-butylamine, 1-aminoisobutane. Compound,
Substituted amines having 2 to about 20 carbon atoms, such as 2- (N, N-dimethylamino) -1-aminoethane,
Amino mercaptans such as 1-amino-2-mercaptoethane, for example methanolamine, 1-amino-3,
3-dimethylpentan-5-ol, 2-aminohexanol, 2 ', 2 "-diethanolamine, 1-amino-2,5-dimethylcyclohexane-4-ol, 2-
Aminopropanol, 2-aminobutanol, 3-aminopropanol, 1-amino-2-propanol, 2-
Amino-2-methyl-1-propanol, 5-aminopentanol, 3-aminomethyl-3,5,5-trimethylcyclohexanol, 1-amino-1-cyclopentanemethanol, 2-amino-2-ethyl-1 Aliphatic alcohols having from 2 to about 20, preferably from 2 to about 12, carbon atoms, such as, 3-propanediol, aromatic-aliphatic amino alcohols having from 6 to about 20 carbon atoms, or Aromatic-alicyclic amino alcohol (where
As aromatic ring structure, a heterocyclic ring system, or preferably a homocyclic ring system such as naphthalene, or especially, for example, 2-aminobenzyl alcohol, 3- (hydroxymethyl) aniline, 2-amino-3-phenyl-1-propanol, 2
Benzene derivatives such as -amino-1-phenylethanol, 2-phenylglycinol or 2-amino-1-phenyl-1,3-propanediol can be used. ) Or a mixture of two or more of these compounds.

The compound used for synthesizing the hard segment and / or the soft segment in the thermoplastic polyurethane may have an anchor group, if necessary.

By anchor group is meant an anionic or cationic functional group or a salt thereof that interacts with a polar surface, for example, the surface of an inorganic filler, by suction. Examples of suitable anchor groups include carboxyl groups, sulfo groups, phosphonate groups, phosphate groups or suitable salts of these groups, or quaternary amino groups or derivatives thereof (eg esters), primary, secondary or tertiary groups. Examples include a secondary amine, a group in which two or more groups included in the same type of anchor group described above, or a mixture of groups included in two or more types of the above anchor groups. Anchor groups are introduced by methods known to those skilled in the art.

In a preferred form of the invention, hard segment B exhibits a glass transition temperature ranging from about 50 ° C to about 160 ° C. In a more preferred form of the invention, the glass transition temperature of hard segment B is from about 100 to about 155C.
, For example, in the range of about 110 to about 150 ° C. To ensure the desired mechanical properties for the new binder, the molecular weight of hard segment B should be about 350
It should be in the range of ~ 15,000. In a preferred form of the invention, the range is from about 500 to about 10,000, such as from about 800 to about 4000 or from about 1000 to about 25.
A hard segment B having a molecular weight in the range of 00 is used.

The synthesis of the soft segment A is performed in accordance with general rules in organic polymer chemistry. When a polyester, polyether, polycarbonate, polyacetal or other compound having a functional group Y and capable of being used as the soft segment is used as the soft segment, the synthesis thereof is performed by those skilled in the art. This is performed using a known method in polymer chemistry. Depending on the bifunctional compound used for molecular chain elongation, when different compounds of the above compounds that can be used as soft segments must be linked together because the molecular weight of the individual compounds is too small. The elongation is carried out in the same manner according to the known general rules of organic chemistry for each functional group.

The reaction of the compound of the formula II suitable as a hard segment with a compound suitable as a soft segment is carried out by a method known per se, preferably at a temperature of about 0 to 120 ° C. The ratio of the two components is preferably selected such that the ratio of Y to NCO groups is from about 2 to about 1. Following the general rules of polymer chemistry, the molecular weight of the resulting thermoplastic polyurethane can be controlled over a wide range by appropriately varying the above ratios.

The invention therefore relates to an inorganic filler, a thermoplastic polyurethane having at least one soft segment A and at least one hard segment B,
Wherein the thermoplastic polyurethane is obtained by reacting at least two components L and M, wherein a) component L

[0059]

Embedded image (Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and n are
Represents the same meaning as given for compound I. B) having a molecular weight of at least 300 as component M;
It also relates to a binder-containing composition, characterized in that at least a bifunctional compound is used, which is capable of reacting with isocyanate groups to form covalent bonds.

For the purposes of the present invention, use is therefore made, as component L, of compounds which are suitable for forming hard segments B having a structural part of the formula I. Also,
Compounds suitable for the synthesis of soft segment A described herein are used as component M. Therefore, the component M
Is a structure YMY (Y represents the same meaning as described above)
Having.

Furthermore, the invention comprises at least one soft segment A and at least one hard segment B, wherein at least one hard segment B has the formula I

[0062]

Embedded image A novel binder-containing composition of the present invention is produced by mixing a thermoplastic block copolyurethane or a mixture of two or more copolyurethanes having a structural portion represented by the formula (I) with an inorganic filler. How to do it. In the formula, R ¹ and R ³ may be the same or different and each represents a substituted or unsubstituted aromatic or heteroaromatic group having 4 to 40 carbon atoms, and R ² and R ⁴ represent Each represents hydrogen, or R ¹ , R ² , R ³ and R ⁴ represent a substantially fully fluorinated alkyl group having 1 to 10 carbon atoms, and R ⁵ and R ⁶ are the same A substituted or unsubstituted linear or branched aliphatic group or a substituted or unsubstituted alicyclic group or a substituted or unsubstituted aromatic group having 4 to 40 carbon atoms, which may be present or different. And n is 1 to 100.

The at least one thermoplastic polyurethane present in the novel binder-containing composition ranges from about 3000 to about 150,000, preferably from 10,000 to 6,000.
It has a molecular weight in the range of zero.

The reaction can be carried out in the presence of a catalyst if necessary. In a preferred embodiment, the catalyst is, for example,
Triethylamine, tributylamine, diazabicyclo
[2.2.2] -octane, N-methylpyridine or N
Using a tertiary amine such as methylmorpholine. Other preferred catalysts include organometallic compounds such as dibutyltin dilaurate, and metal salts such as tin octoate, lead octoate, and zinc stearate. The amount of catalyst used in the reaction is generally about 1 to about 5
It is in the range of 00 mass ppm.

[0065] Solvents or diluents are generally not required. However, in a preferred embodiment, one solvent or a mixture of two or more solvents is used. Examples of suitable catalysts include hydrocarbons, especially toluene, xylene or cyclohexane; esters, especially ethyl glycol, ethyl acetate or butyl acetate; amides, especially dimethylformamide or N-methylpyrrolidone; sulfoxides, especially dimethylsulfoxide; Especially diisopropyl ether or methyl t-butyl ether;
Or preferably cyclic ethers, especially tetrahydrofuran or dioxane;

In the synthesis of thermoplastic polyurethane, if a compound suitable as a soft segment is used in excess of the corresponding compound of the formula II forming a hard segment, a functional group Y is added to the chain end. The resulting thermoplastic polyurethane is synthesized. For the synthesis of the thermoplastic polyurethanes of the formula II, a compound having a terminal group capable of reacting with isocyanate groups is reacted with a compound which is bifunctional with respect to such groups,
Chain extension can be performed. The corresponding bifunctional compound of the formula XZX has a functional group X that reacts with a functional group Y. Examples of such a functional group X mainly include an isocyanate group, and a preferred embodiment of the present invention uses an isocyanate group. However, depending on the type of functional group Y, X may also be another functional group capable of reacting with Y, for example an epoxy group, a carboxyl group, a carboxylic anhydride or a carbonyl halide.

In a preferred form of the invention, Z has as functional group X at least two epoxy, OH, NCO or COOH groups or a mixture of two or more of these groups which do not react with one another.

The novel binder-containing composition of the invention comprises at least one thermoplastic segment B having at least one hard segment B, ie at least one hard segment B having a structural part of the formula I Including polyurethane. In a preferred form of the invention, the novel binder-containing composition comprises at least about 1%, preferably at least about 5%, particularly preferably at least about 10% by weight of the total binder-containing composition, It comprises a thermoplastic polyurethane or a mixture of two or more such thermoplastic polyurethanes. In addition to the thermoplastic polyurethanes described above, the novel binder-containing composition further comprises another thermoplastic polyurethane or a mixture of two or more such polyurethanes without the corresponding structural part of Formula I You may go out.

In a further preferred embodiment of the invention, the novel binder-containing composition according to the invention also comprises, in addition to the thermoplastic polyurethane or a mixture of two or more of said polyurethanes having a structural part of the formula I , At least one
Including another polymer of the species.

The novel binders according to the invention can also comprise, besides the thermoplastic polyurethanes mentioned above or a mixture of two or more thereof, another polymer or a mixture of two or more other polymers. Other polymers that can be used for the novel binder include polyurethane, polyacrylate, polyester polyurethane, polyacrylate urethane or polymethacrylate urethane, polymethacrylate, polyacrylamide, styrene, vinyl chloride, vinyl acetate, Polymers or copolymers of vinyl monomers such as vinyl propionate, binders based on vinyl formal, cellulose esters, especially polymers containing cellulose such as cellulose nitrate, cellulose acetate, cellulose acetopropionate, cellulose acetobutyrate, the process itself Include a phenoxy resin or an epoxy resin obtained by a known method, or a mixture of two or more thereof.

The novel binder-containing compositions of the present invention generally comprise up to about 100% by weight of a thermoplastic polyurethane having a structural part of the formula I. The other polymer is present in the novel binder in an amount of up to about 80% by weight, for example up to about 70%, 60%, 50%, 40% or 30% by weight or less. May be.

The novel binder-containing composition of the present invention can be used both as a dispersion binder and as a topcoat binder.

In a preferred form of the invention, the novel binder contains one magnetic powder or a mixture of two or more magnetic powders. Suitable magnetic powders are γ-Fe ₂ O ₃ , γ-F
e ₃ O _4, a conventional oxide powder or Fe, metal powder such as Co, and Ni, such as CrO _2, Co-modified Fe ₂ O _3. Generally, other elements or compounds can be mixed with these powders.

In addition, the novel binder-containing compositions include fillers, dispersants, lubricants, carbon black or other additives such as non-magnetic inorganic powders or non-magnetic organic powders. You may go out.

For the production of the novel magnetic dispersions, therefore, the thermoplastic polyurethanes or mixtures of two or more of these polyurethanes can be combined, for example, with one or more magnetic powders or a mixture of two or more magnetic powders. As a mixture with a solvent, and, if necessary, fillers, dispersants,
It is dispersed with other binders and lubricants, carbon black or other additives such as non-magnetic inorganic powders or non-magnetic organic powders. In a preferred form, the main components of the magnetic dispersion, especially the powder and the binder, are first added and mixed with a small amount of solvent in order to obtain a paste material, and then, for example, kneaded and mixed well with each other, and then dispersed. Just let me do.

For example, carboxylic acids having about 10 to about 20 carbon atoms, especially stearic acid or palmitic acid, or derivatives of carboxylic acids such as salts, esters or amides of carboxylic acids, or two or more of these. The mixture can be used as a lubricant.

Suitable non-magnetic, inorganic additives include, for example, alumina, silica, titanium dioxide or zirconium dioxide, and suitable non-magnetic, organic powders include, for example, polyethylene and polypropylene.

In the case of their use in magnetic recording media, the novel binders are applied, for example, on conventional rigid or flexible substrates. Suitable substrate materials include, for example, generally about 4 to about 200 μm, especially about 5 to 36 μm.
m and a film of a linear polyester such as polyethylene terephthalate or polyethylene naphthalate.

The invention therefore also relates to the use of the novel binders or the binders prepared according to the invention for the production of magnetic recording media, and to such recording media themselves. Examples of recording media are, inter alia, professional and end-user video cassettes, professional and end-user audio cassettes, such as digital audio tapes, diskettes, floppy disks, ZIP disks, magnetic disks. And a strip.

Hereinafter, examples of the present invention will be described.

Example 1) Synthesis of a binder a) Hard segment (polydiisocyanate) Azine and diisocyanate are weighed in a ratio of 0.6 to 1.0, and as a melt at 165 to 175 ° C, the theoretical NCO
The reaction was continued until the content was reached. The mechanism of the reaction is a cross-cycloaddition reaction.

Three different types of hard segments were synthesized and summarized in Table 1 below. The azine used is always p-
It was methoxybenzoaldazine. The molecular weight was measured by a GPC method in THF using polystyrene as a standard sample. The glass transition temperature was measured by the DSC method at a heating rate of 20 K / min.

[0083]

[Table 1]

The product of the cycloaddition reaction is brittle, transparent,
It is a slightly yellowish resin.

B) Binder The polydiisocyanate and the polyester polyol were weighed in equimolar amounts and heated at 65 ° C. in THF for 4 hours.
The catalyst used was dibutyltin dilaurate.

[0086]

[Table 2]

2) Dispersions Dispersion experiments were performed on binders 6 and 7. For this purpose, the magnetic powder DOWA HW 31 was pre-dispersed with the given binder (see Table 3) and the dispersant stearic acid by methods known to those skilled in the art. Gloss was measured as an evaluation of the dispersibility of this first stage,
Thereafter, binders 6 and 7 were added to complete the second stage dispersion.

[0088]

[Table 3]

3) Comparative Example When a binder without a conventional anchor group was used instead of the novel binder, the gloss in the second stage was reduced compared to the gloss in the first stage. This means
This indicates that the dispersibility has deteriorated. To investigate this relationship, the magnetic powder DOWA HW 31 and the binder CA151HT (from Morton) and the dispersant stearic acid were first predispersed by methods known to those skilled in the art. After measuring the gloss as an evaluation of the dispersibility in this first stage, a polyurethane-based binder without anchor groups was added and the dispersion was completed in the second stage.

[0090]

[Table 4]

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Benedict, Letter Germany, 67061, Ludwigshalfen, Rubensstraße, 27 (72) Inventor Ulrike, Haas Germany, 68161, Mannheim, Korinichstrasse, 12a (72 Inventor Leah, Cress Germany, 67063, Ludwigshalfen, Gartenstrasse, 5 (72) Inventor Albert, Cole Germany, 67229, Laumersheim, Schlossstrasse, 26 (72) Inventor Richard, Bradshaw United States, Arizona, 85748, Toerson, N. Schrader, L.N., 330 (72) Inventors Gehhard, Meier Germany, 80807, Munich, Ingol Süeter, Strase, 1

Claims (11)

[Claims] An inorganic filler and at least one soft segment A and at least one hard segment B
A thermoplastic block copolyurethane having at least one hard segment B, wherein the at least one hard segment B has the formula I (Wherein, R ¹ and R ³ may be the same or different, and a substituted or unsubstituted aromatic or heteroaromatic group having 4 to 40 carbon atoms is represented by R ² and R ⁴ Represents hydrogen, or R ¹ , R ² , R ³ and R ^{4 each} have 1 to 1 carbon atoms.
Represents zero substantially fully fluorinated alkyl groups, wherein R ⁵ and R ⁶ may be the same or different and are substituted or unsubstituted straight-chain having 4 to 40 carbon atoms. Represents a chain or branched aliphatic group or a substituted or unsubstituted alicyclic group or a substituted or unsubstituted aromatic group, and n is 1 to 100. A) a binder-containing composition comprising a structural part represented by 2. The binder-containing composition according to claim 1, wherein R ¹ and R ³ each represent a methoxybenzyl group or a trimethoxybenzyl group, and R ² and R ⁴ each represent hydrogen. 3. R ⁵ and R ⁶ may be the same or different and each have a substituted or unsubstituted linear or branched aliphatic group having 4 to 10 carbon atoms, 6 atoms
The binder-containing composition according to claim 1, which represents １８18 substituted or unsubstituted aromatic groups. 4. The binder-containing composition according to claim 1, which comprises a magnetic powder or a magnetizable powder as an inorganic filler. 5. The method according to claim 1, wherein the thermoplastic block copolyurethane or a mixture of two or more copolyurethanes comprises at least one other polymer. A binder-containing composition of 6. The at least one other polymer includes polyacrylate; polyester polyurethane; polyacrylate urethane or polymethacrylate urethane; polymethacrylate; polyacrylamide; styrene, vinyl chloride, vinyl acetate, vinyl propionate. Polymers or copolymers of vinyl monomers, such as; binders based on vinyl formal; polymers containing cellulose, such as cellulose esters, for example cellulose nitrate, cellulose acetate, cellulose acetopropionate, cellulose acetobutyrate; phenoxy resins or epoxies 6. The binder-containing composition according to claim 5, comprising a polymer selected from the group consisting of a resin; or a mixture of two or more thereof. 7. A thermoplastic block copolyurethane or a copolyurethane having a structural part of the formula I in the hard segment B in an amount of up to 100% by weight, based on the total binder-containing composition. The binder-containing composition according to any one of claims 1 to 6, wherein the composition comprises a mixture of: 8. An inorganic filler and at least one soft segment A and at least one hard segment B
A binder-containing composition comprising: a thermoplastic block copolyurethane having the formula: wherein said thermoplastic block copolyurethane is obtained by reacting at least two components L and M, the reaction comprising: a) component L is a compound of formula II (Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and n are
Represents the aforementioned meaning. B) as component M, having a molecular weight of at least 300,
The binder-containing composition according to any one of claims 1 to 7, wherein at least a bifunctional compound capable of reacting with an isocyanate group to form a covalent bond is used. 9. Component M is a polyester, polyether, polyacetal, polycarbonate, polyacrylate, polymethacrylate, or vinyl polymer, which is at least difunctional to isocyanate groups, or two or more polymers. The binder-containing composition according to claim 8, wherein a mixture of these is used. 10. A thermoplastic block copolyurethane having at least one soft segment A and at least one hard segment B or a mixture of two or more such copolyurethanes, comprising at least one inorganic filler and at least one soft segment A and at least one hard segment B. The hard segment B has the formula I (Wherein, R ¹ and R ³ may be the same or different, and a substituted or unsubstituted aromatic or heteroaromatic group having 4 to 40 carbon atoms is represented by R ² and R ⁴ Represents hydrogen, or R ¹ , R ² , R ³ and R ^{4 each} have 1 to 1 carbon atoms.
Represents zero substantially fully fluorinated alkyl groups, wherein R ⁵ and R ⁶ may be the same or different and are substituted or unsubstituted straight-chain having 4 to 40 carbon atoms. Represents a chain or branched aliphatic group or a substituted or unsubstituted alicyclic group or a substituted or unsubstituted aromatic group, and n is 1 to 100. The binder-containing composition according to any one of claims 1 to 9, by mixing a thermoplastic block copolyurethane having a structural portion represented by the formula or a mixture of two or more copolyurethanes with each other. How to manufacture. 11. The method according to claim 1, wherein the magnetic recording medium is manufactured.
A method of using the binder-containing composition according to any one of claims 9 to 9.